Exprimental Study of Ultrasound on MDR in a Human Tumor in Vivo

Objective To evaluate the potential efficacy of low-intensity ultrasound (US) in combination with anticancer drugs to reverse multidrug resistance (MDR) in nude mice. Methods A total of 40 male and female athymic nude mice were inoculated subcutaneously with 5×10⁶ HepG₂/ADM and HepG₂ cells. Ultrasound with pulsed irradiation at an average intensity of 0.5 W/cm² was given to the tumor area 10 min after administration of adriamycin (ADM). The tumor 3 dimensional diameters were measured by calipers before and after treatment, and the tumor growth indexes (TGI) calculated. RT-PCR was used to detect the gene levels of the HepG₂/ADM cells. Immunohistochemical analyses for MDR proteins were conducted on the tumor tissues. Results The ultrasonic treatment resulted in an average reduction in the tumor volume of 62% one month later. The relative mRNA levels of MDR1 and MRP were significantly different among the following 4 groups: untreated group as control, ADM treated; US treated; and ADM plus US treated. The mRNA levels of mdr1 and mrp were down-regulated in the US groups compared to those of the non-ultrasound groups by multiple comparisons. The relative mRNA levels of lrp expression were not significantly changed. The results of immunohistochemistry indicated that tumor tissue from animals treated with US had remarkably low mdr1 and mrp expression. Conclusion The results showed that low-intensity US can effectively reduce the size of adriamycin-resistant human hepotacarcinoma in a nude mouse model, and support the efficacy of US to overcome multiple mechanisms of drug resistance. This work was supported by a grant from the National Natural Science Foundation of China (No. 30200060).     

Reversal of Adriamycin Resistance of Hepatocellular Carcinoma by Targeting with Recombined Adenovirus Caning Antisense mdr1 RNA

OBJECTIVE Chemotherapy is an important therapy for hepatocellular carcinoma (HCC). However, it is not effective in many cases due to recurrence and metastasis even if the initial treatment produces a response. Multidrug resistance (MDR) is considered to be one of the considerable causes. The aim of this study was to reverse MDR of HepG2/ADM cells by blocking mdr1 with an adenovirus vector carrying antisense mdr1 in a tumor transplantated in athymic mice. METHODS pCMV IE was removed from the pshuttle vector. A 0.3 kb AFP promoter was inserted into the pshuttle vector and pCMV changed into pAFP. The pAFP and asmdr1 PCR products were doubly digested with Kpnl and Apal, the digested products were ligated by T4 ligase, the asmdrl gene was inserted into pAFP and a newly plasmid pAFP-asmdr1 was constructed. Following digestion with PI-Scel/l-Ceu l, pAFP-asmdr1 was ligated with Adeno-X genome DNA and amplified in E.coli XL 1-Blue. The HEK293 cells were transfected and virus collected. The HepG2 MDR cells (HepG2/ADM) were induced by graded resistance to ADM and were inoculated into athymic mice. After adeno-asmdr1 was injected, the expression of mdr1 -mRNA and the volume of the transplantated tumor and its cells were observed. RESULTS Following injection with Adeno-asmdr1, the tumor volume in the ADM Adeno-asmdr1 group did not increase. However the tumor volume in the PBS plus ADM group did significantly increase (P<0.05). In the tumor xenograft cells, mdr1 mRNA in the xenografts was assessed by RT-PCR and was found to be reduced at 1 week and 4 weeks in the ADM asmdr1 group, but it was stable in the ADM group. It was only 20% in the ADM asmdr1 group compared to the ADM group at the 4th week (P<0.05). Evidence of apoptosis was observed in the tumor xenograft cells treated with Adeno-asmdr1, but there was rare or no apoptosis in the group treated with ADM and PBS. CONCLUSION Adenovirus carrying antisense mdr1 RNA can partially reverse the MDR of HepG2/ADM cells and inhibit tumor growth by down-regulating mdr1 mRNA resulting in tumor cell apoptosis.     

人肝癌移植瘤多药耐药模型的建立及耐药机制的探讨

背景与目的肿瘤多药耐药是肿瘤化疗的主要障碍和研究热点,本研究拟建立人肝癌裸小鼠皮下及肝原位移植多药耐药模型,探讨其生物学特性和耐药机制的异同,为研究体内逆转肿瘤多药耐药提供理想的动物模型。方法人肝癌细胞系HepG2裸鼠肝原位、皮下移植后,用阿霉素腹腔注射诱导耐药。MTT法检测耐药细胞对抗肿瘤药的敏感性,流式细胞仪检测癌细胞膜蛋白P-糖蛋白(P-gp)、多药耐药相关蛋白(MRP)、肺耐药蛋白(LRP)的表达和细胞对罗丹明(R123)的外排作用,逆转录PCR检测耐药细胞中三种膜蛋白mRNA的表达。结果肝原位和皮下移植瘤耐药细胞形态及生物学行为符合人肝癌特征;对多种药物产生较明显的耐药性,其中对阿霉素的耐药倍数分别为26.4和24.6;肝皮下移植和原位移植组耐药细胞膜蛋白P-gp、MRP和LRP的阳性率均增高,分别为(77.3±2.1)%和(78.1±1.9)%,(72.1±4.3)%和(72.7±5.1)%,(31.1±1.0)%和(32.2±1.4)%。多药耐药基因的阳性率也明显增高,细胞对R123的外排作用增强;肝原位移植瘤组与皮下移植瘤组比较,多药耐药性差异没有统计学意义(P>0.05)。结论所建立的裸鼠肝原位及皮下移植瘤多药耐药模型符合人肿瘤多药耐药特征,为研究体内逆转多药耐药提供了理想的动物模型。     

Reversal of Adriamycin Resistance of Hepatocellular Carcinoma by Targeting with Recombined Adenovirus Carring Antisense mdr1 RNA

OBJECTIVE Chemotherapy is an important therapy for hepatocellular carcinoma （HCC）. However, it is not effective in many cases due to recurrence and metastasis even if the initial treatment produces a response. Multidrug resistance （MDR） is considered to be one of the considerable causes. The aim of this study was to reverse MDR of HepG2/ADM cells by blocking mdr1 with an adenovirus vector carrying antisense mdr1 in a tumor transplantated in athymic mice. METHODS PCMV IE was removed from the pshuttle vector. A 0.3 kb AFP promoter was inserted into the pshuttle vector and pCMV changed into pAFP. The pAFP and asmdr1 PCR products were doubly digested with Kpnl and Apal, the digested products were ligated by T4 ligase, the asmdr1 gene was inserted into pAFP and a newly plasmid pAFP-asmdr1 was constructed. Following digestion with PI-SceI/I-Ceu I, pAFP-asmdr1 was ligated with Adeno-X genome DNA and amplified in E.coli XL1-Blue. The HEK293 cells were transfected and virus collected. The HepG2 MDR cells （HepG2/ADM） were induced by graded resistance to ADM and were inoculated into athymic mice. After adeno-asmdr1 was injected, the expression of mdr1-mRNA and the volume of the transplantated tumor and its cells were observed. RESULTS Following injection with Adeno-asmdr1, the tumor volume in the ADM＋Adeno-asmdr1 group did not increase. However the tumor volume in the PBS plus ADM group did significantly increase （P〈0.05）. In the tumor xenograft cells, mdr1 mRNA in the xenografts was assessed by RT-PCR and was found to be reduced at 1 week and 4 weeks in the ADM＋asmdr1 group, but it was stable in the ADM group. It was only 20% in the ADM＋asmdr1 group compared to the ADM group at the 4th week （P〈0.05）. Evidence of apoptosis was observed in the tumor xenograft cells treated with Adeno-asmdr1, but there was rare or no apoptosis in the group treated with ADM and PBS. CONCLUSION Adenovirus carrying antisense mdr1 RNA can partially reverse the MDR of HepG2/ADM cells and inhibit tumor growth by down-regulating mdr1 mRNA resulting in tumor cell apoptosis.     

HIFU逆转人肝癌细胞HepG2/Adm多药耐药的实验研究

背景与目的：超声波能够改变细胞膜通透性,增强化疗药物对肿瘤细胞的杀伤作用。本研究评价高强度聚焦超声及其联合阿霉素(Adriamycin,ADM)对人肝癌多药耐药细胞株HepG2／Adm的效应,并探讨其作用机制。方法：取对数生长期的HepG2、HepG2／Adm细胞进行实验,分为HepG2、HepG2(超声波照射5s)、HepG2／Adm、HepG2／Adm(超声波照射5s)4组。用MTT法检测处理前后耐药细胞对抗癌药物的敏感性;用流式细胞仪检测肿瘤细胞表面mdr1基因表达产物P170的表达及细胞内阿霉素浓度;利用SP免疫组化法观察细胞膜及核膜上P-糖蛋白(P-glycoprotein,P-gp)的表达。结果：频率0.8MHz、焦域声强460W／(cm^2连续照射5s,能够部分逆转HepG2／Adm细胞的耐药性,HepG2／Adm细胞P-gp的表达活性下降83．1％,耐药细胞内ADM浓度增加88％,对ADM、cDDP、MMc、5-FU和MTX相对逆转效率分别为66．4％、63．4％、89．4％、72．4％和75．0％。结论：高强度聚焦超声可提高人肝癌细胞HepG2／Adm内药物浓度,降低细胞膜及核膜表面P-gp表达,从而部分逆转肿瘤细胞多药耐药。     

阿霉素诱导人肝癌细胞多药耐药株的建立及其生物学特性评价

背景与目的:多药耐药(multidrugresistance,MDR)是肿瘤治疗的主要障碍,为探讨体外逆转肿瘤MDR的新方法,本研究建立人肝癌细胞多药耐药模型HepG2/Adm,并研究其生物学特性。方法:以人肝癌细胞株HepG2为研究对象,用阿霉素(adriamycin,ADM)浓度梯度递增诱导法,建立HepG2/Adm。观察细胞的生长规律;用MTT法检测多药耐药性;流式细胞术检测细胞周期分布、细胞表面多药耐药基因(mdr1)的表达产物P-糖蛋白(P-glycoprotein,P-gp)、多药耐药相关蛋白(multidrugresistance-associatedprotein,MRP)、肺耐药蛋白(lung-relatedprotein,LRP)及谷胱甘肽S-转移酶(glutathioneS-transferase,GST)的表达;逆转录PCR半定量检测4种MDR基因mRNA表达量。结果:与HepG2细胞比较,HepG2/Adm细胞倍增时间延长30.01h,S期细胞减少(5.6±0.03)%,G1、G2期细胞增多犤(4.2±0.09)%,(1.5±0.08)%犦。该细胞对多种抗肿瘤药物耐药,HepG2/Adm对阿霉素的耐药指数是亲本细胞的26倍,细胞表面多药耐药蛋白P-gp、MRP及GST的表达显著增加,LRP表达有一定的增加;上述四种耐药蛋白基因的表达均明显增加。结论:HepG2/Adm细胞具有多药耐药特性,其耐药性与P-gp、MRP及GST的过表达有关。     

蝎毒多肽提取物对白血病细胞株K562/A02荷瘤鼠耐药性的影响

目的 探讨蝎毒多肽（peptide extract from scorpion venom,PESV）逆转白血病干细胞（leukemiastem cells, LSC）在体内多药耐药（multidrug resistance, MDR）的分子机制。方法 以多药耐药的K562/A02细胞株成模白血病BALB/c裸鼠为例,成模鼠随机分为6组：模型对照组、阿霉素（ADM）组、PESV组、ADM+PESV（H）组、ADM+PESV（M）组、ADM+PESV（L）组。模型对照组给予等体积0.9%氯化钠溶液腹腔注射,其余各组予相应剂量ADM和（或）PESV腹腔注射,连续给药14天。第21天观察各组裸鼠移植瘤生长情况,分别检测瘤块中LSC：细胞膜上P-gp的表达,细胞质中ALDH、PI3K的变化及细胞核中MDR1、NF-κB的活性。结果 K562/A02细胞经免疫磁珠分选前后的CD34+CD38-细胞比率和IC50值分别为31.5%、（60.33±10.68）μg/ml和92.8%、（58.33±9.72）μg/ml,分选后细胞干性显著提高,而耐药性无差异性损失;各组造模裸鼠成瘤率100%。瘤体中LSC：流式细胞仪检测细胞膜上P-gp表达结果：检测对照组89.8%、ADM组91.9%、PESV组88.4%、ADM+PESV（H）组53.9%、ADM+PESV（M）组78.0%、ADM+PESV（L）组78.7%;半定量RT-PCR检测MDR1 mRNA的表达：PESV组＞ADM+PESV（L）组＞ADM+PESV（M）组＞ADM+PESV（H）组＞ADM组;免疫组织化学检测ALDH,显示灰度值ADM组＞PESV组＞ADM+PESV（H）组＞ADM+PESV（M）组＞ADM+PESV（L）组;Western blot检测PI3K分子与Elisa检测NF-κB因子结果一致,在ADM组、PESV组表达上调,在ADM+PESV组中表达下调,下调强度与PESV剂量呈正相关。结论 PESV具有下调白血病干细胞膜上P-gp,细胞质内ALDH、PI3K及细胞核中MDR1、NF-κB的表达水平,增强了白血病K562/A02干细胞在体内对ADM的敏感度,逆转其多药耐药特性。     

人参皂苷Rg3对小鼠肺腺癌多耐药的逆转作用

目的观察人参皂苷Rg3对小鼠肺腺癌多耐药的逆转作用并探讨其机制。方法 将32只接种获得性多药耐药Lewis肺癌细胞的小鼠随机分成4组:荷瘤对照组、多柔比星(ADM)组、人参皂苷Rg3组和人参皂苷Rg3联合多柔比星(ADM)组。各组予以相应干预,观察肿瘤生长情况,肿瘤接种24天处死全部小鼠,剥取皮下移植肿瘤,称瘤重,计算抑瘤率,收集移植瘤标本行免疫组织化学检测P-糖蛋白(P-glycaprotein,p-Gp)和多药耐药相关蛋白1的表达,并行RT-PCR半定量检测多药耐药基因(multidrug resistance,MDR1)mRNA、多药耐药相关蛋白1(multidrug resistance-associated protein 1,MRP1)mRNA表达。结果 (1)各用药组肿瘤的生长受到不同程度抑制,瘤重低于对照组,其抑瘤率分别为10.5%、36.3%、56.2%,联合用药组抗瘤作用进一步增强。(2)免疫组织化学:p-Gp及MRPl蛋白质的表达具有一致性,对照组和ADM组表达较高,而人参皂苷Rg3组和联合组表达明显降低,其中对照组和ADM组比较,人参皂苷Rg3组和联合组比较,差异无统计学意义(P>0.05);而人参皂苷Rg3组和联合组与对照组和ADM组比较差异均有统计学意义(P<0.01)。(3)RT-PCR:与对照组和ADM组比较,人参皂苷Rg3组和联合组MDR1 mRNA荧光强度降低,人参皂苷Rg3组、联合组同对照组及ADM组比较MDR1 mRNA相对量减小,差异均有统计学意义(P<0.01),而对照组同ADM组比较,人参皂苷Rg3组同联合组比较差异未见统计学意义,MRP1 mRNA的表达与MDR1 mRNA类似。结论 人参皂苷Rg3对小鼠肺腺癌多药耐药有逆转作用,其作用机制可能是下调MDR1 mRNA、MRP1 mRNA及其蛋白的表达。     

Establishment and characterization of new cellular lymphoma model expressing transgenic human MDR1

Multidrug resistance (MDR) due to the expression of the MDR1 gene and its P-glycoprotein (Pgp) product is a major factor in the prognosis and clinical outcome of patients with refractory lymphomas and other malignancies. The aim of our study was to establish a lymphoma, cellular system where a de novo acquisition of multidrug resistance is specifically related to overexpression of a transgenic, human MDR1. A multidrug sensitive lymphoma cell line (LM1) was established from a sporadic T-cell lymphoma of BALB/c mouse and was transduced by a retroviral vector containing the human MDR1 cDNA. The resultant cell variant (LM1/MDR) was characterized in comparison to the parental LM1 cells. The LM1/MDR cell variant is cross-resistant to DOX, COL, ACT D and VBL. This cell variant expresses the human MDR1 and exhibits de novo functional Pgp activity that can be blocked by the Pgp-modulators VRP and KT-5720. The acquired MDR of LM1/MDR is not accompanied with gene amplification, alternative splicing or up-regulation of the murine endogenous mdr1a, mdr1b, mrp1, mrp2 and mrp3 transporter-genes. Therefore, the acquired MDR is, specifically, human MDR1-dependent as it has been found in malignant cells of most lymphoma patients. Moreover, this system can be used as a model to study MDR and the efficacy of drugs and modulators on malignant cells where human Pgp is a major factor of multidrug resistance.     

导向逆转剂Ab-IL2体外偶联以及协同抑瘤作用的研究

探讨利用乳腺癌单克隆抗体作为导向载体,将逆转剂IL2特异性地导向肿瘤细胞,使其发挥逆转作用的临床应用价值,为将此方法用于肿瘤的临床治疗提供医学依据。方法：分别制备人基因重组白细胞介素2（IL-2）以及人乳腺癌单克隆抗体（记为Ab）,将其经过体外的偶联与纯化,并对偶联产物进行严格的质量检测,最终得到导向多药耐药（MDR）逆转剂Ab-IL2,并通过体外MDR逆转作用检测其活性保留。将对阿霉素（ADM）耐药的人乳腺癌细胞系MCF-7/ADM,种植于BALB/c裸鼠皮下,每只小鼠注射量为106个细胞,将得到的荷瘤小鼠分为三组,并于接种后的第14,19天分别进行如下处理：1）对照组：腹腔注射生理盐水;2）ADM组：腹腔注射阿霉素（1 mg/kg体重）;3）协同用药组：同时注射阿霉素（1 mg/kg体重）和前述实验获得的多药耐药逆转剂Ab-IL2（1 mg/kg体重）。分别于14、16、18、20天测量肿瘤大小,并于第20天处死小鼠,取出瘤块并称重,据此计算肿瘤抑瘤率。结果：Ab-IL2的质量合格,活性保留为90.7%。多药耐药逆转剂Ab-IL2与阿霉素联合应用显示出体内协同抑瘤作用,至第20天处死小鼠时,协同用药组的抑瘤率为60.48%,是ADM组（抑瘤率19.44%）的3.11倍。结论：将单克隆抗体介导技术应用于肿瘤MDR导向逆转,可以促进逆转剂有效地发挥其应有的作用,本研究为实现临床上MDR逆转剂的成功应用提供了有力保证。     

Reversal of drug resistance of hepatocellular carcinoma cells by adenoviral delivery of anti-ABCC2 antisense constructs

Human cancers are characterized by a high degree of drug resistance. The multidrug resistance transporters MDR1-P-glycoprotein (ABCB1) and ABCC2 (MRP2) are expressed in a variety of human cancers, including hepatocellular carcinoma (HCC). The ABCC2 gene encodes a membrane protein involved in the ATP-dependent transport of conjugates of lipophilic substances. In this study we analyzed the effect of an ABCC2 antisense construct on the chemosensitization of HepG2 cells. Adenoviral vectors were constructed to allow an efficient expression of anti-ABCC2 antisense constructs. The effective target sequence comprised nucleotides 2543-2942 of the human ABCC2 cDNA. Adenoviral delivery of the ABCC2 antisense construct resulted in a reduced IC(50) for doxorubicin (12-fold), vincristine (50-fold), cisplatin (25-fold) and etoposide (VP-16) (25-fold). The adenoviral delivery of the ABCC2 antisense construct was so efficient that chemosensitization of HepG2 cells could even be demonstrated in mass cell cultures without a selection of transduced cells for single ABCC2 antisense-expressing HCC cell clones. After transfection of the ABCC2 antisense-expressing construct, HepG2 cells had significantly reduced ABCC2 mRNA and ABCC2 protein levels. Transduction of the ABCC2 antisense-expressing construct into HepG2 cells resulted in the accumulation of the high-affinity ABCC2 substrate Fluo-3. HepG2 tumors stably transfected with an anti-ABCC2 antisense construct regressed significantly in nude mice upon vincristine treatment. In addition, significant tumor regression was also observed when adenovirus-expressing anti-ABCC2 antisense construct was directly injected into HepG2 tumors in nude mice. Our study demonstrates the specific reversal of ABCC2-related drug resistance in adenovirus-transduced HepG2 cells and in HepG2 tumors in nude mice expressing this ABCC2 antisense construct.     

转ARL-1基因HepG2细胞耐药相关基因的筛选

背景与目的:醛糖还原酶相似基因1(aldose-reductaselikegene-1,ARL-1)在原发性肝癌中高表达,与肝癌细胞对化疗药物耐药有关。本研究拟建立转染ARL-1的人肝癌细胞株,观察转染ARL-1的HepG2细胞对含醛基抗肿瘤药物耐药性的改变,利用基因表达谱芯片筛选HepG2细胞转染ARL-1后差异表达耐药相关基因。方法:采用脂质体转染PBK/ARL-1质粒到HepG2细胞,获得高表达ARL-1的单克隆细胞株;RT-PCR、流式免疫荧光和免疫组化鉴定高表达ARL-1的HepG2细胞;应用MTT法和细胞凋亡分析研究HepG2细胞和转染ARL-1的HepG2细胞对含醛基抗肿瘤药物阿霉素(ADM)和丝裂霉素(MMC)的耐药性,以5-氟尿嘧啶(5-FU)(不含醛基)为对照;将Cy3和Cy5两种荧光染料分别标记两种细胞的cDNA探针,与人肝癌基因表达谱芯片进行杂交与扫描,观察转染ARL-1基因HepG2与对照组HepG2细胞在基因表达谱方面的差异,筛选耐药相关基因,并运用RT-PCR和Westernblot对部分差异表达相关基因进行初步证实。结果:与对照组HepG2细胞相比,转染ARL-1基因HepG2细胞高表达ARL-1蛋白,明显增强对含醛基的抗肿瘤药物如ADM、MMC的耐药性,分别提高2.6倍和3.47倍,用5-FU处理两组细胞,则未发现有明显的耐药差异(ADM组t=6.39,P<0.05;MMC组t=30.06,P<0.01;5-FU组t=0.684,P>0.05);芯片扫描结     

多药耐药细胞系K562/A02裸小鼠皮下移植瘤模型的建立与鉴定

目的:建立一种耐药特性稳定的裸小鼠移植瘤动物模型,为进行体内肿瘤耐药机制研究和逆转药物的筛选提供实验模型和实验基础。方法:将具有典型MDR表型的K562/A02耐药细胞接种于裸小鼠右侧背侧皮下,而亲本K562细胞接种裸小鼠左侧背侧皮下,接种细胞数为1×10⁷细胞/只,观察肿瘤成瘤情况及生长特性,并比较裸小鼠移植瘤细胞和体外培养细胞对化疗药物的敏感性,同时利用RT-PCR和免疫组织化学染色对裸小鼠K562/A02移植瘤基因表型进行鉴定。结果:1)K562/A02裸小鼠移植瘤的成瘤率为100%,大约于第6～9天成瘤(体积>100mm³),敏感肿瘤生长速度与耐药肿瘤无明显差别;2)裸小鼠K562/A02移植瘤肿瘤细胞和体外培养原代细胞对阿霉素的IC₅₀分别为185.24μg/ml和235.25μg/ml,而K562/A02移植瘤肿瘤的IC₅₀分别为3.07μg/ml和3.26μg/ml;阿霉素治疗组能够明显减慢K562敏感移植瘤的生长,而对K562/A02耐药移植瘤的生长几乎无作用;3)K562/A02裸小鼠移植瘤肿瘤细胞具有mdr1/Pgp表达,而K562裸小鼠移植瘤肿瘤细胞则无mdr1/Pgp表达。结论:以K562/A02细胞建立的裸小鼠耐药移植瘤模型,仍保持近似体外的耐药活性和基因表型,为耐药机制和逆转研究提供了良好的体内模型。     

RNAi对白血病细胞mdr-1基因和多药耐药表型的影响

目的:探讨RNA干扰技术(RNAi)对慢性粒细胞白血病急变细胞系K562/AO2细胞mdr1基因的抑制和耐药表型的逆转作用。方法:选择合成封闭mdr-1基因的小干扰序列(si-MDR1),以1个碱基突变的si-MDR1-mut为对照序列,在脂质体介导下转染至K562/AO2细胞系。RT-PCR和Western blot检测mdr1 mRNA及P-gp蛋白水平,流式细胞术分析细胞内柔红霉素(daunorubicin,DNR)积累量,并以四甲基唑蓝快速比色法(MTT)反映K562/AO2对阿霉素、长春新碱、足叶乙甙药物敏感性的变化。结果:实验证实该序列能高效封闭K562/AO2细胞内mdr-1基因表达,增加细胞内化疗药物DNR积累量,增强K562/AO2细胞对阿霉素、长春新碱、足叶乙甙的敏感性。结论:RNAi可以通过抑制mdr1基因表达,逆转K562/AO2细胞耐药表型。     

人肺腺癌移植瘤多药耐药模型建立及生物学特性的研究

目的:建立耐药特性稳定的肺腺癌移植瘤裸小鼠动物模型,为进行耐药机制研究及逆转药物筛选提供实验模型和实验基础。方法:A549/DDP细胞接种于小鼠右侧腋下,观察肿瘤成瘤情况及生长特性;MTT法检测耐药倍数;RT-PCR和免疫组织化学染色检测小鼠移植瘤多药耐药1(MDR1)和多药耐药相关蛋白1(MRP1)的基因及蛋白表达。结果:移植瘤细胞和原代细胞对DDP的耐药倍数无差异。移植瘤成瘤率均为100%,于第6～9天成瘤(体积>100mm3)。与A549移植瘤相比,A549/DDP移植瘤成瘤潜伏期短(P=0.002),生长速度快。移植瘤中MDR1和MRP1 mRNA及P-糖蛋白(P-gp)和MRP1蛋白的相对表达量均升高,差异有统计学意义,P=0.000。结论:以A549/DDP细胞建立的肺癌多药耐药裸小鼠移植瘤模型,保持耐药活性和基因表型。